Counterbalance dual completion unit



Oct. 9, 1962 w. J. GOURLEY 3,057,213

COUNTERBALANCE DUAL COMPLETION UNIT Filed April 24, 1962 m WILLIAM JGOURLEY INVENTOR.

ATTORNEY rates tent . fic

3,057,213 COUNTERBALANQE DUAL COMPLETION UNIT William J. Gourley, Fort Worth, Tex, assignor to American Manufacturing Company of Texas, Fort Worth,

Tex, a corporation of Texas Filed Apr. 24, 1962, Ser. No. 191,673 2 Claims. (Ci. 74-41) This invention relates to pumping units and has reference to improved means for counterbalancing beam type pumping units when producing multiple completion oil wells. This application is a continuation in part of my copending application, Serial No. 51,156, filed August 22, 1960, and now abandoned. The term multiple completion as herein used has reference to producing oil from two or more depths through the same bore hole and may consist of separate tubing strings extending to each producing formation or may consist of one or more tubing strings within the well bore and employing the casing as a means for producing from one of the formations. Since the producing zones are at different depths the weights of the separate strings of sucker rods are different. Thus, each pumping unit should be separately counterbalanced. If each pumping unit has its own power unit, counterbalancing is accomplished in the usual manner, but the capital investment and maintenance costs are greater than two pumping units having a single power source. Heretofore, two or more units having a single power source. Heretofore, two or more units having a single power source were connected with each other by flexible or semiflexible means, but such means depended, at least in part, on the weight of the separate sucker rods strings to maintain the flexible means in tension. Such arrangement could not provide optimum counterbalancing of the units. Moreover, such flexible connections would not accommodate fast pumping, nor could one of the individual units remain in balance if another unit was disconnected.

An object of the invention is to provide optimum counterbalancing in two connected beam type pumping units producing a multiple completion well and having a single power source.

Another object, in addition to the foregoing object, is to provide means whereby one unit will remain in balance if the other unit is disconnected therefrom or if there is change of loads therein, for example, if the sucker rod string of one unit breaks.

A further object is to provide, in two connected pumping units for multiple completion wells, means whereby the two units may be operated at high speed when required.

These and other objects of the invention will become apparent from the following description and the accompanying drawings, wherein:

The FIGURE is a side elevational view of the invention shown in operating position with respect to the tubing strings and casing of a dually completed well.

In the drawing, the upper end of the top stand of a casing projects above the surface of the ground and is provided with a casing head 11. The surface stands of primary and secondary tubing strings 12 and 13 extend through the casing head 11 into the casing 10 and respectively communicate with pumps (not shown) positioned at different levels within the well. The tubing strings 12 and 13 communicate with separate outlet pipes 14 and 15 above the casing head 11 and each tubing string is provided with a stuffing box 16 and 17 at its upper end. A rectangular platform 18 is supported by the surface of the ground and is constructed of two coplanar sections 19 and 20 having adjacent edges 21 and 22 provided with opposed semi-circular recess (not shown) to accommodate the upper end of the casing 10. Straps 23 extend between and are attached to the two sections 19 and 20 of the platform to secure the same to the casing 10.

A primary Samson post 24, shown constructed of forward and rear legs 25 and 26 which are inclined toward one another and joined at their upper ends, is attached to and supported by the larger section 19 of the platform 18 at a position thereon spaced from the casing 10. A saddle bearing pin 27 is supported by the upper end of the primary Samson post 24 and is there disposed with its axis perpendicular to the alignment between the top of the Samson post and the principal axis of the casing 10. A primary walking beam 28 is pivotally attached intermediate its ends to the pin 27 for angular displacement in a vertical plane common with the axis of the casing 10 and with the axes of the tubing strings 12 and 13. A mulehead 29 is mounted on one end of the primary walking beam 28 and is provided with an arcuate face 30 formed on a radius from the pivot pin 27 and positioned in tangential relationship to the axis of the primary tubing string 12. A bridle 31 extending over and depending from the arcuate face 31% of the mulehead 29 engages and supports the upper end of a polished rod 32 which extends into the primary tubing 12 through its stuffing box 16 and which is connected to a sucker rod string (not shown) which, in turn, is in operating engagement with a pump (not shown) in the lower end of the tubing string 12. A primary rocker frame 33 is comprised of two elongate structural members 34 and 35 respectively attached to the walking beam 28 at opposite sides of the pin 27 and extending convergingly downward at one side of the walking beam to a point of intersection laterally spaced from the primary Samson post 24. The lower extremity of the rocker frame 33 lies in a plane common with the axes of the pin 27 and perpendicular to the length of the primary walking beam 28.

A secondary Samson post 36 is attached to and supported by the smaller section 20 of the platform 18 at a position thereon opposite but equidistant from the casing 10 with respect to the primary Samson post 24. The construction of the secondary Samson post 36 is identical to that of the primary Samson post 24 and includes upwardly converging forward and rear legs 37 and 38 which support a saddle bearing pin 39. In like manner, a secondary walking beam 40 is pivotally connected to the pivot pin 39 for vertical displacement and carries a mulehead 41 from which a bridle 42 depends and supports the polished rod 43 of a sucker rod string extending to a pump (not shown) in the base of the secondary tubing string 13. A secondary rocker frame 44 is attached to the secondary walking beam 40 and is comprised of two elongate structural members 45 and 46 respectively attached to the secondary walking beam at opposite sides of its pin 39, and extending downward in laterally spaced relationship from the secondary Samson post 36 to a point of intersection lying in a plane perpendicular to the length of the secondary walking beam and common with the axis of its pin 39. The primary and secondary rocker frames 33 and 44 are substantially coplanar and are positioned at the same side of the two Samson posts 24 and 36; the dimensions of the two rocker frames shown are substantially identical.

A rigid link 47 is pivotally attached at its opposite ends to the two rocker frames 33 and 44 at the lower extremities thereof, and the distance between the pivotal attachments of the link to the rocker frames corresponds to the distance between the pivot pins 27 and 39 of the primary and secondary Samson posts 24 and 36.

A motor 48 having its drive shaft 49 disposed parallel to the axes of the pivot pins 27 and 39 is supported by the platform 18 at a position rearward of the primary Samson post 24. A gear reduction box 50 having a driven shaft '51 and a crank shaft 52 is attached to the platform 18 at a position between the motor 48 and the primary Samson post 24 and is disposed with its shafts parallel with the drive shaft 49 of the motor. A drive sheave 53 attached to the drive shaft 49 of the motor 48 is engaged by a belt 54 which also engages a driven sheave 55- mounted on the driven shaft 51 of the gear reduction box 50. A crank 56 attached to the crankshaft 52 of the gear reduction unit is pivotally connected by a crank pin 57 to one end of a pitman 58 which is pivotally connected at its other end to the primary walking beam 28. A counterbalance 59 is attached to the crank 56 in the preferred embodiment of the invention but it is to be understood that the counterbalance may be mounted at other positions, not shown, without departing from the spirit of the present invention. A conventional longitudinally adjustable counterbalance 61 is mounted on the secondary walking beam 40 for independently balancing the secondary unit.

An understanding of the problems and principles involved in the eflicient counterbalancing of a pumping unit is helpful in an explanation of the operation of the invention. On the upstroke of a submerged pump, the mulehead of its pumping unit carries both the weight of the sucker rods and the weight of the fluid column within the tubing. On the downstroke, however, the weight of the fluid column is supported by the check valve of the pump in the base of the tubing, and the mulehead supports only the weight of the sucker rods. Hence, there is a weight difference between the two strokes which equals the weight of the fluid column. The effective Weight of a counterbalance is, therefore, made to equal the weight of the sucker rods plus one-half the weight of the fluid column; equal forces are then required to displace the sucker rod in opposite directions.

The motor and gear box of the present invention drive a single crank 56- pivotally attached to the pitman 58 which reciprocates the primary walking beam 28. Both the primary and secondary walking beams 28 and 40 are provided with correspondingly arranged rocker frames 33 and 44 preferably of equal dimensions, and the rigid link 47 coacting the rocker frames drives the mulehead 47 of the secondary unit downward when the mulehead 29 of the primary unit is raised.

The invention is not limited to the exemplary construction herein shown and described, but may be made in various ways within the scope of the appended claims.

What is claimed is:

1. In a multiple completion well having at least two sucker rod strings within a single bore hole, a first beam type pumping unit having its walking beam in engagement with one of said sucker rod strings, means reciprocating said walking beam of said first pumping unit, a second beam type pumping unit having its walking beam in vertical planar alignment with said walking beam of said first pumping unit and in engagement with the other said sucker rod string, a rocker arm rigidly attached to said walking beam of said first pumping unit and projecting substantially vertically and perpendicularly from the length thereof, a second rocker arrn rigidly attached to the walking beam of said second pumping unit and projecting substantially vertically and perpendicularly from the length thereof, a rigid link pivotally connected at its ends to both said rocker arms, said rigid link being of sufficient strength to carry both compression and tension loads during pumping operations, and counterbalances mounted on each of said units, the counterbalance weight of each said unit being substantially equal to the weight of the sucker rod string plus one-half the weight of the oil lifted thereby.

2. In a multiple completion well having at least two sucker rod strings within a single bore hole, a first beam type pumping unit having its walking beam in engagement with one of said sucker rod strings, counterbalance means mounted on said first pumping unit and adjustably mounted for substantially optimum balance, means reciprocating the walking beam of said first pumping unit, a second beam type pumping unit having its walking beam in vertical planar alignment with the walking beam of said first pumping unit and in engagement with the other said sucker rod string, a rocker arm rigidly attached to said walking beam of said first pumping unit and projecting substantially vertically and perpendicularly from the length thereof, a second rocker arm rigidly attached to said second pumping unit and projecting substantially vertically and perpendicularly from the length thereof, a rigid link pivotally connected at its ends to said rocker arms, said rigid link being of sufficient strength to carry both compression and tension loads during pumping operations, and counterbalance means mounted on the said second unit and adjustable for substantially optimum balance.

References (Jited in the file of this patent UNITED STATES PATENTS 431,442 Cook July 1, 1890 1,501,226 Malbaif July 15, 1924 1,780,933 Martois et al. Nov. 11, 1930 2,035,525 Bloss Mar. 31, 1936 2,153,094 Maier Apr. 4, 1939 2,179,649 Trout et al. Nov. 14, 1939 2,265,379 Lyne Dec. 9, 1941 2,910,002 Morgan Oct. 27, 1959 

